<let/count = 0/>
<div>
  <button onClick() { count++ }>${count}</button>
  <div>
    <let/count = 0/>
    <button onClick() { count++ }>${count}</button>
    <div>
      <let/count = 0/>
      <button onClick() { count++ }>${count}</button>
    </div>
  </div>
</div>
<div>
  <let/count = 0/>
  <button onClick() { count++ }>${count}</button>
</div>